Goal 2
Explore for past or present habitable environments,
prebiotic chemistry and life that might exist elsewhere in our Solar System.
Characterize ancient climates, any extinct life and potential habitats for extant life on Mars, and determine the presence of life's chemical precursors and potential habitats in the outer Solar System.
The exploration for habitable environments, life and/or prebiotic chemistry in the Solar System directly links basic research in astrobiology to NASA missions. The fundamental requirements for life as we presently understand them include liquid water and also environments favorable for the assembly of complex organic molecules and energy sources to sustain metabolism. Because we presently know so little about any such environments within our Solar System, the first steps in exploration are to determine the distribution and nature of potentially habitable environments. Although life elsewhere could have developed in ways different from life on Earth, we logically begin with our current knowledge as we plan our exploration strategy. Research in such widely divergent areas as planetary and Solar System evolution, the biology of extreme environments, and Precambrian paleontology have been instrumental in informing NASA about how to search for evidence of life elsewhere in the Solar System, or beyond. Earth-based analog studies and theoretical investigations, informed by data from previous Solar System missions, will assist astrobiologists to refine exploration strategies and scientific priorities for future missions. An important task is to continue to strengthen the interactions between the various disciplines that have contributed to the growth of this new field.
- Objective 2.1—Mars
exploration. Through orbital and
surface missions, explore Mars for potentially habitable environments,
as evidenced by water or aqueous minerals. Study Martian meteorites
to guide future Mars exploration. Develop the methods and supporting
technologies for the in situ characterization of aqueous minerals, carbon
chemistry and/or life.
- Objective 2.2—Outer Solar System exploration. Conduct basic research, develop instrumentation to support astrobiological exploration and provide scientific guidance for outer Solar System missions. Such missions should explore the Galilean moons of Jupiter, Europa, Ganymede and Callisto, for habitable environments where liquid water could have supported prebiotic chemical evolution, or life. Saturn's moon, Titan, should be explored for environments favorable for complex prebiotic synthesis or life.